This invention relates to a disk carrier and more particularly to a carrier for carrying memory disks during the manufacture of such disks such that both surfaces of the disks can be processed simultaneously.
Many methods of manufacturing memory disks for use, for example, in disk drives as well as apparatus to be used therefor have been known. U.S. Pat. Nos. 4,595,481 and 4,634,512 disclose disk carriers with a carrier plate having a plurality of generally circular throughholes of approximately of the size of the disks to be processed and a recessed area of a slightly larger circle formed around the top half of each of these circular throughholes. The inner walls of the throughholes are grooved along their lower halves such that each disk to be processed can be brought first to the slightly larger recessed area either manually or by a robot and then positioned in the groove at the bottom with its both surfaces exposed through the throughhole.
Since the memory disks intended for such carriers are highly fragile and easily damaged, they are currently handled almost exclusively by an automated handling apparatus. Before a robot can mount or remove a disk on or from a carrier, however, it is essential that the position of the carrier, or more specifically the position on the carrier intended for the disk be accurately determined. For this reason, use may be made of a touch sensor, for example, of the type disclosed in U.S. Pat. No. 4,734,549 having a generally pointed contact part with a spherical external surface at its forward end and sets of indexing depressions may be provided on the surface of the carrier plate. U.S. Pat. No. 4,735,701 discloses a carrier plate provided with such indexing depressions formed at equidistant positions from mutually adjacent pairs of the throughholes and the touch sensor serves to detect the three-dimensional coordinates of these depressions to instruct the robot where the next disk should be mounted or removed. Operating a touch sensor to bring its pointed contact part successively from one such indexing depression to another, however, is a cumbersome job and providing such indexing depressions specifically for this purpose adds to the manufacturing cost of the disk carrier.